After several more failed attempts to remove the frozen piston, I had resigned myself to the fact that the cylinder was likely damaged beyond repair and decided a caustic bath was the best way forward. To that end I mixed up a dose (stronger than that advised above) placed the cylinder c/w frozen piston in it and watched it fizz for the next couple of hours.
Approx 6 hours later, I noticed the fizzing had stopped. Thinking this meant the piston had completely dissolved, I extracted the cylinder only to find the piston still intact and frozen to the cylinder albeit now black in color. Back in she goes with a few more caps of caustic for good measure. Now approaching midnight so hopeful piston will be gone by the morning!
Well guess what? That didn’t happen. Piston was still in place and not moveable by hand, so it’s now make or break time. Holding a large metal rod against the gudgeon housing, I proceeded to pound away with a hammer and slowly but sure the piston began to fall apart and move. Out finally
To my surprise there were only a few marks in the cylinder walls, however overall the cylinder is not suitable for use again and will end up as part of a display piece.
to give you an idea what I was dealing with, the following pic if of one half the broken crank. You can see by the heavy rust and corrosion, that this poor old dear had been underwater at some stage. Cylinder was in much the same shape when I started.
A pic of many of the parts rescued and some not. Note this Seasprite was purchased as a parts outboard only. I was primarily after the gearbox and prop to resolve issues with another Seasprite that will be fully restored down the track.
Thanks again to all who gave support and advice. It's always very much appreciated.
Regards,
